Error: circular initialization dependency with module actor

[Orgoton]

Queue (class) has
"public Queue AIQ;"
defined at the end of the module file. This Queue is used on the default
constructor of Actor (a class). There is no static constructor on Actor. The only
static thing on Queue is the symbol above. Queue however must store a list of
Actor's, hence it has an array of Actor. That is a private member of the Queue
class. Is this the origin of "Error: circular initialization dependency with
module actor"? Why didn't I have this error with previous versions?